Transducers for use in medical ultrasound imaging applications generate heat during use. The FDA imposes limits on the maximum temperature that a patient contact surface may attain. The prior art has suggested various ways of cooling an ultrasonic transducer during operation. U.S. Pat. No. 5,560,362 to Sliwa Jr. et al. teaches various methods for providing active cooling to a transducer structure, per se, i.e., a closed loop circulating cooling system, a thermoelectric cooler and an evaporator/condenser system. In the embodiments described in the '362 patent, there is little consideration given to electronics which might be incorporated with the transducer.
U.S. Pat. No. 5,163,433 to Kagawa et al. and No. 4,748,985 to Nagasaki both disclose ultrasonic imaging heads with incorporated channels for the conduction of cooling liquid about an ultrasonic transducer structure.
As requirements placed upon the performance of ultrasound transducers have steadily increased, it has become important to capture the ultrasound signals as close to the transducer as possible. In this regard, electronic circuits have been incorporated directly into the housing which holds the transducer. So long as power dissipation from such circuits has been held to a minimum, the heat generated from such circuits has been able to be dissipated by straightforward conduction to an outer surface of the casing. However, as signal processing complexities required of such circuits has increased, the dissipated power has likewise increased. Accordingly, to preserve patient comfort and to enable transducer operation in a continuous manner, additional means must be found to provide necessary cooling of the included electronics. There is thus a need for improved means for cooling electronics incorporated into the housing of an ultrasound transducer. Further, there is a need to provide improved cooling means for integrated circuits incorporated into the ultrasound transducer housing.